The present invention relates to substrates, and more specifically, to a connection to a substrate.
Various devices are often attached to substrates. In some cases, such devices are encased in a conductive receptacle. The conductive receptacle is attached to mounting holes in the substrate.
FIG. 1 illustrates one prior art attachment mechanism. The substrate (PCB) 110 includes a number of mounting holes 120, 150, for connecting various components to the substrate 110. A device is attached to the substrate 110 using a mounting screw 140. (the device is not shown for clarity). Two types of mounting holes 120, 150 are illustrated. A first mounting hole 120 is drilled through the substrate 110. The first mounting hole 120 includes a plating 130 of tin or solder on the inside of the mounting hole. This plating 130 contacts the back-side 160 of the substrate 110. The back-side 160 of the substrate 110 includes a ground plane 170. Thus, if the conductive receptacle is coupled to the first mounting hole 120, the conductive receptacle is grounded. The conductive receptacle is coupled though the plating 130 to the ground plane 170. This grounds the conductive receptacle to the ground plane 170.
A second mounting hole 150 is also shown. The second mounting hole 150 is not plated. Therefore, if the conductive receptacle is coupled to the second mounting hole 150, the conductive receptacle is not grounded.
In the prior art, the decision to ground a receptacle must be made prior to manufacturing, when the substrate 110 is initially designed. Either the receptacle is designed to be grounded, or the receptacle is designed to be not grounded. One prior art solution to this is the inclusion of two sets of mounting holes 120, 150 in the substrate. If the receptacle is to be grounded, the receptacle is attached to a first, plated, mounting hole set 120. If the receptacle is not to be grounded, the receptacle is attached to a second, non-plated, mounting hole set 150. This means that the traces and connections to the receptacle are duplicated around each set of mounting holes 120, 150. Additionally, more real-estate is used on the substrate 110. And, finally, half the mounting holes 120, 150 are not used, since for each receptacle two sets of mounting holes 120, 150 are prepared. This increases manufacturing cost and complexity.
A connection system to a substrate is described. The system includes a substrate having a mounting hole designed to permit an object to be coupled to the substrate. The substrate further includes a conductive pattern around the mounting hole on the substrate. The conductive pattern is designed to contact an interface, and selectively couple a signal to the object coupled to the substrate.